<nb-card>
  <nb-card-header>疑问反馈</nb-card-header>
  <nb-card-body>
    <textarea rows="15" nbInput fullWidth shape="round" name="content" [(ngModel)]="content" placeholder="请输入您的留言"></textarea>
    <br>


  </nb-card-body>
  <nb-card-footer>
    <button nbButton style="float: right;" (click)="submit()" class="btn-hero btn btn-large btn-primary">提交</button>
  </nb-card-footer>
</nb-card>
